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Mathematical modelling of WOX5- and CLE40-mediated columella stem cell homeostasis in Arabidopsis.

Richards S, Wink RH, Simon R - J. Exp. Bot. (2015)

Bottom Line: We have also found that WOX5 contributes to, but is not absolutely necessary for, CSC maintenance.Furthermore, our modelling led us to postulate an additional signalling molecule that promotes CSC maintenance.We propose that this WOX5-independent signal originates in the QC, is targeted by CLE40 signalling and is capable of maintaining CSCs.

View Article: PubMed Central - PubMed

Affiliation: Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany.

No MeSH data available.


Values of W determine cell fate, represented by FCC and FQC. The numerical representatives of CC and QC fate (FCC and FQC respectively), were modelled as Hill functions dependent on W. Parameters Wa and Wb determine their half-maximum values. Cells with values of W<Wa, Wa<W<Wb, and W>Wb would be classified as CC, CSC and QC cell, respectively.
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Figure 2: Values of W determine cell fate, represented by FCC and FQC. The numerical representatives of CC and QC fate (FCC and FQC respectively), were modelled as Hill functions dependent on W. Parameters Wa and Wb determine their half-maximum values. Cells with values of W<Wa, Wa<W<Wb, and W>Wb would be classified as CC, CSC and QC cell, respectively.

Mentions: To that end, we first developed a simple single-cell model, where the fate of a cell is controlled entirely by the interactions and different concentrations of a WOX5-derived signal (W) and the signalling peptide CLE40 (C). To keep the model simple, we assumed that everything necessary for the function of W and C (e.g. RLKs necessary for signal transmission) was abundant. In order to incorporate QC, CSC and CC fates into a mathematical model, numerical representatives of cell fate were required. These representatives could then be used to specify production rates of the two factors W and C, allowing us to require C to be produced by CCs, but not by CSCs or the QC. The representatives could also determine the fate of a cell, so that cells with insufficient concentrations of W differentiate into CCs as they do under experimental conditions. We designated variables FCC and FQC as the representatives, with high values of FCC representing CC fate and high values of FQC representing QC fate. Both FCC and FQC vary between 0 and 1 (Fig. 2) as a function of W. Parameters Wa and Wb are the half-maximum values of FCC and FQC, respectively. The value of FQC increases with W concentration, simulating the WOX5-dependent aspects of QC fate. A cell with W>Wb would be categorized as a QC cell. Low values of W yield higher values of FCC, simulating differentiation to CC fate when W concentration is insufficient for CSC maintenance. We would categorize a cell with W<Wa as having CC identity and a cell with any value of W between Wa and Wb as having CSC identity.


Mathematical modelling of WOX5- and CLE40-mediated columella stem cell homeostasis in Arabidopsis.

Richards S, Wink RH, Simon R - J. Exp. Bot. (2015)

Values of W determine cell fate, represented by FCC and FQC. The numerical representatives of CC and QC fate (FCC and FQC respectively), were modelled as Hill functions dependent on W. Parameters Wa and Wb determine their half-maximum values. Cells with values of W<Wa, Wa<W<Wb, and W>Wb would be classified as CC, CSC and QC cell, respectively.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526915&req=5

Figure 2: Values of W determine cell fate, represented by FCC and FQC. The numerical representatives of CC and QC fate (FCC and FQC respectively), were modelled as Hill functions dependent on W. Parameters Wa and Wb determine their half-maximum values. Cells with values of W<Wa, Wa<W<Wb, and W>Wb would be classified as CC, CSC and QC cell, respectively.
Mentions: To that end, we first developed a simple single-cell model, where the fate of a cell is controlled entirely by the interactions and different concentrations of a WOX5-derived signal (W) and the signalling peptide CLE40 (C). To keep the model simple, we assumed that everything necessary for the function of W and C (e.g. RLKs necessary for signal transmission) was abundant. In order to incorporate QC, CSC and CC fates into a mathematical model, numerical representatives of cell fate were required. These representatives could then be used to specify production rates of the two factors W and C, allowing us to require C to be produced by CCs, but not by CSCs or the QC. The representatives could also determine the fate of a cell, so that cells with insufficient concentrations of W differentiate into CCs as they do under experimental conditions. We designated variables FCC and FQC as the representatives, with high values of FCC representing CC fate and high values of FQC representing QC fate. Both FCC and FQC vary between 0 and 1 (Fig. 2) as a function of W. Parameters Wa and Wb are the half-maximum values of FCC and FQC, respectively. The value of FQC increases with W concentration, simulating the WOX5-dependent aspects of QC fate. A cell with W>Wb would be categorized as a QC cell. Low values of W yield higher values of FCC, simulating differentiation to CC fate when W concentration is insufficient for CSC maintenance. We would categorize a cell with W<Wa as having CC identity and a cell with any value of W between Wa and Wb as having CSC identity.

Bottom Line: We have also found that WOX5 contributes to, but is not absolutely necessary for, CSC maintenance.Furthermore, our modelling led us to postulate an additional signalling molecule that promotes CSC maintenance.We propose that this WOX5-independent signal originates in the QC, is targeted by CLE40 signalling and is capable of maintaining CSCs.

View Article: PubMed Central - PubMed

Affiliation: Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany.

No MeSH data available.